#include<stdio.h>

int main()
{
	float ave=0;
	int num=2;
	float pricesum=0.0;
	int day=0;
	while(num<100)
	{
		pricesum+=num*0.8;
		num=num*2;
		day++;
	}
	ave=pricesum/day;
	printf("平均花钱数为:%f\n",ave);
	
	
	return 0;
}